Chen Winson X, Poon Eric K W, Hutchins Nicholas, Thondapu Vikas, Barlis Peter, Ooi Andrew
a Department of Mechanical Engineering , Melbourne School of Engineering, The University of Melbourne , Parkville , Australia.
b Faculty of Medicine, Dentistry & Health Sciences, Department of Medicine , The University of Melbourne , Parkville , Australia.
Comput Methods Biomech Biomed Engin. 2017 May;20(6):671-681. doi: 10.1080/10255842.2017.1289374. Epub 2017 Feb 9.
The haemodynamic behaviour of blood inside a coronary artery after stenting is greatly affected by individual stent features as well as complex geometrical properties of the artery including tortuosity and curvature. Regions at higher risk of restenosis, as measured by low wall shear stress (WSS < 0.5 Pa), have not yet been studied in detail in curved stented arteries. In this study, three-dimensional computational modelling and computational fluid dynamics methodologies were used to analyse the haemodynamic characteristics in curved stented arteries using several common stent models. Results in this study showed that stent strut thickness was one major factor influencing the distribution of WSS in curved arteries. Regions of low WSS were found behind struts, particularly those oriented at a large angle relative to the streamwise flow direction. These findings were similar to those obtained in studies of straight arteries. An uneven distribution of WSS at the inner and outer bends of curved arteries was observed where the WSS was lower at the inner bend. In this study, it was also shown that stents with a helical configuration generated an extra swirling component of the flow based on the helical direction; however, this extra swirl in the flow field did not cause significant changes on the distribution of WSS under the current setup.
冠状动脉支架置入术后，冠状动脉内血液的血流动力学行为受到支架个体特征以及动脉复杂几何特性（包括迂曲度和曲率）的极大影响。通过低壁面切应力（WSS < 0.5 Pa）测量的再狭窄高风险区域，在弯曲的支架置入动脉中尚未得到详细研究。在本研究中，使用三维计算建模和计算流体动力学方法，采用几种常见的支架模型分析弯曲的支架置入动脉中的血流动力学特征。本研究结果表明，支架支柱厚度是影响弯曲动脉中WSS分布的一个主要因素。在支柱后方发现了低WSS区域，特别是那些相对于流向成大角度的支柱。这些发现与在直动脉研究中获得的结果相似。在弯曲动脉的内弯和外弯处观察到WSS分布不均匀，内弯处的WSS较低。在本研究中还表明，具有螺旋结构的支架根据螺旋方向产生了额外的流动涡旋分量；然而，在当前设置下，流场中的这种额外涡旋并未导致WSS分布发生显著变化。
